By designing a vending machine in Java or any other object-oriented language, you not only learn basics e.g. Encapsulation, Polymorphism, or ...PagesHomecorejavaspringhibernatecollectionsmultithreadingdesignpatternsinterviewquestionscodingdatastructureOOPjava8booksAboutMeJavaCertificationsJDBCjsp-servletJSONSQLLinuxCoursesonlineresourcesjvm-internalsRESTEclipsejQueryJavaIOJavaXMLDesignaVendingMachineinJava-InterviewQuestionHowdoyoudesignaVendingMachineinJava?isoneofthegoodJavainterviewquestionsmostlyaskedatSeniorlevelJavadeveloperInterviews.Inatypicalcodinginterview,youwillbegivenaproblemstatementtodevelopavendingmachineandwithinalimitedtime,usually,2to3hoursyouneedtoproduceadesigndocument,workingcode,andunittestinJava.OneofthekeyadvantagesofsuchJavainterviewsisthatyoucantestmanyessentialskillsoracandidateinonego.Inordertocompletethedesign,coding,andunittestingofaVendingmachine,acandidateneedstobereallygoodinallthreedepartments.Bytheway,thiskindofreal-worldproblemisalsoagoodexercisetoimproveyourobject-orientedanalysisanddesignskills(seehere),whichisveryimportantifyouwanttobecomeagoodapplicationdeveloper.BydesigningavendingmachineinJavaoranyotherobject-orientedlanguage,younotonlylearnbasicse.g.Encapsulation,Polymorphism,orInheritancebutalsolearnssubtledetailsofhowtouseanabstractclassandinterface(seehere)whilesolvingaproblemordesigninganapplication.Usually,thiskindofproblemalsogivesyouanopportunitytoutilizeJavadesignpatterns,asinthisproblemwewillbeusingtheFactorymethodpatternforcreatingdifferenttypesofVendingMachine.IhavetalkedaboutthisquestionwhenIshared20softwaredesignquestionsinJava(here),andafterthat,Ireceivealotoffeedbacktoprovideasolutionforthatquestion.Thistwo-partseriesofpostswillprovideasolutiontotheVendingmachineprobleminJava.Bytheway,thisproblemcanbesolvedinadifferentway,andyoushouldtrytodothatbeforelookingintothesolutiongivenhere.ThisisalsoanopportunitytorevisitSOLIDandOOPSdesignprinciples(seehere)andgetreadytousetheminyourcode.You'llfindmanyofthemareappli